1. Technical Field
The present invention relates to an inertial sensor.
2. Description of the Related Art
Recently, an inertial sensor has been used as various applications, for example, militaries such as an artificial satellite, a missile, an unmanned aerial vehicle, or the like, vehicles such as an air bag, an electronic stability control (ESC), a black box for a vehicle, or the like, a hand-shaking preventing device for a camcorder, a motion sensing device of a mobile phone, a game machine, a navigation, etc.
The inertial sensor generally uses a configuration of bonding a mass body to a flexible substrate such as a diaphragm, etc., in order to measure acceleration and angular velocity. Through the configuration, the inertial sensor may yield the acceleration by measuring an inertia force applied to the mass body and yield the angular velocity by measuring a Coriolis force applied to the mass body.
However, when the excessive force is applied to the mass body, a support portion of the mass body may be damaged. In particular, when the inertial sensor collides with a ground by the free fall thereof, a very large force is applied to the mass body and thus, it is highly likely to damage the support portion of the mass body. Therefore, there is a need to include a physical structure in order to limit the displacement of the mass body in a predetermined range. However, in order to limit the downward displacement of the mass body, the inertial sensor according to the prior art includes a lower substrate and the lower substrate should be provided with a separate convex portion corresponding to the downward displacement of the mass body. Therefore, the manufacturing process of the inertial sensor is complicated and it is difficult to precisely control the thickness of the convex part corresponding to the downward displacement, thereby degrading the mass body production of the inertial sensor.